The present invention relates to a programmable controller system and a reset controlling method for the programmable controller system.
A conventional programmable controller system will be explained with reference to FIG. 7. This programmable controller system is provided with a power-supply unit 500 for supplying power to the system, a CPU unit 510 which forms a center of the system for executing the operation processing for the control, an output unit 520 for outputting ON/OFF information to an external apparatus 600 based upon an instruction outputted by a CPU unit 510, a data link unit 530 for executing data communication between systems (affiliated stations 610) through dedicated lines and a positioning unit 540 connected to a servo-motor 620 for carrying out a positioning control. These units are attached to a mother board 550 containing a system bus (hereinafter, referred to as a base unit), that is, bus-connected.
In the explanation that follows, the output unit 520, the data link unit 530, etc., which are controlled by the CPU unit 510, are generally referred to as an I/O unit.
The CPU unit 510 is provided with a reset circuit 512 in addition to the microprocessor (MPU) 511. The reset circuit 512 unifies an error signal for preliminarily informing the power-supply down sent from the power supply system (power-supply reset signal: hereinafter, referred to as xcexa3REL signal) and an error signal (hereinafter, referred to as CPUERRL signal) due to an operation error, etc., generated by the microprocessor 511 so that a reset signal (hereinafter, xcexa3MRE signal) for controlling the resetting operation with respect to the I/O unit of the programmable controller system is outputted.
When both of the xcexa3REL signal and the CRUERRL signal are non-active (H-level) in the reset circuit 512, since no currents are allowed to flow through the diodes 513 and 514, the base electric potential of the transistor 515 is set to the High level, thereby allowing a current to flow through the emitter and collector of the transistor 515 so that the xcexa3MRE signal is set to the L level (non-active).
For example, when the power-supply unit 500, which has detected the power-supply down due to the power supply off, outputs the xcexa3REL signal in the L-level, a current flows in the forward direction through the diode 513, thereby setting the base electric potential of the transistor 515 to the L-level, stopping the current to flow between the emitter and collector of the transistor 515, and setting the xcexa3MRE signal to the H-level (active) correspondingly.
Moreover, in the event of an operation error in the MPU 511, the CPU unit 510 outputs the CPUERRL signal in the L-level so as to reset the I/O unit to the initial state. When the CPUERRL signal is set to the L-level, a current is allowed to flow in the forward direction of the diode 514, thereby setting the base electric potential of the transistor 515 to the L-level, with the result that no current is allowed to flow between the emitter and collector of the transistor 515 and the xcexa3MRE signal is set to the H-level (active).
In such a case when an operation error occurs in the MPU 511 inside the CPU 510, by a resetting control of the MPU 511 for setting the CPUERRL signal to the L-level so as to set the I/O unit in the initial state, or by the power-supply ON/OFF operation and the resulting reset control in which the power-supply unit 500 has set the xcexa3REL to the L-level thereby setting the I/O unit in the initial state, the xcexa3MRE signal is transmitted to all the units (the output unit 520, data link unit 530, and positioning unit 540) through the base unit 550.
Upon receipt of the xcexa3MRE signal of the H-level, the output unit 520 clears the latch of the output section 521, thereby turning the external apparatus 600 off. The data link unit 530 inputs signals of H-level to the RESET terminals of the control section 531 and the transfer I/F section 532 so that the control section 531 and the transfer I/F section 532 are reset to the initial state, thereby disconnecting the network.
The positioning unit 540 resets the control section 541 to the initial state by inputting signals of H-level to the RESET terminal of the control section 541 and the CLR terminal of the output section 542, and also clears the latch of the output section 542 so as to stop the driving operation of the servo motor 620.
In the conventional programmable controller system as described above, since the resetting system is limited to one system, the resetting control is available only as to whether or not the entire system is reset, and it is not possible to individually reset each unit.
Moreover, in the conventional programmable controller system, when an attempt is made to reset each unit individually, the same circuits as the reset circuit 512 the number of which is as many as the number of the respective units need to be installed in the CPU unit 510 and reset signals corresponding to xcexa3MRE the number of which is the same as the number of the units need to be provided in the inside of the CPU unit 510 and the base unit 550; however, in the programmable controller system in which the number of units to be connected are freely determined by the user, from a realistic point of view, it is impossible to install those many circuits and control signals.
Moreover, with respect to the conventional programmable controller system, when the control section 541 of the positioning unit 540 is driven out of control, the CPU unit 510 issues a reset signal by outputting the CPUERRL signal in the L-level in order to initialize the control section 541 of the positioning unit 540, and this case causes a problem in which the data link unit 530 is further reset to cut off the net work, etc., and the resulting problem is that the system management becomes ineffective.
Moreover, in the conventional programmable controller system, when the system is stopped due to an operation error, etc., inside the CPU unit 510, a resetting signal is issued so as to clear the output, and this case causes a problem in which the data link unit 530 is further reset to cut off the net work, etc., and the resulting problem is that the system management becomes ineffective.
Furthermore, in the conventional programmable controller system, since each unit is not reset individually, the resulting problem is that it is not possible to control the system by altering the number of units of the CPU units 510 to a single or a plural number by using a programmable controller system using the same base unit 550.
Therefore, in a programmable controller system using the same base unit, the objective of the present invention is to provide a programmable controller system which makes it possible to reset-control individual I/O units by using a single CPU unit or a plurality of CPU units.
The present invention relates to a reset controlling method of a programmable controller system which is provided with a single or a plurality of CPU units for carrying out the control of the entire system and a plurality of I/O units that are operated under a control of the CPU units, and in such are set controlling method, the CPU unit writes a command for instructing a control CPU specified information for each I/O unit, each I/O unit decodes a command instructed by the CPU unit so as to determine whether or not it is information specified by the control CPU, and holds the corresponding information specified by the control CPU in the I/O unit, the CPU units issue commands for instructing the reset control to all the I/O units, and each I/O unit decodes the command instructing its reset control, and when it has determined that the corresponding command is instructed from the CPU unit of the controlling end, it follows the reset controlling instruction so that the resetting operation of the specific I/O unit on the system specified by the CPU unit is controlled. Therefore, only the specific I/O unit on the system that is specified by the CPU unit can be reset.
Moreover, in the present invention, with respect to instructions for issuing a reset to each of the I/O units, the CPU unit is provided with two kinds of instructions for reset-controlling the control section of the I/O unit and for reset-controlling the output section of the I/O unit. Therefore, it is possible to individually reset the control section and the output section of the I/O unit.
The present invention also relates to a reset controlling method of a programmable controller system which is provided with a single or a plurality of CPU units for carrying out the control of the entire system and a plurality of I/O units that are operated under a control of the CPU units, and in such a reset controlling method, the CPU unit is provided with two systems of a signal for reset-controlling the control section of the I/O unit and a signal for reset-controlling the output section of the I/O unit as reset signals that are issued to the entire system by the CPU unit, and by utilizing the two signals independently, the resetting of the I/O unit is carried out individually between the control section and the output section. Therefore, the resetting control of the I/O units on the entire system is carried out in a divided manner between the resetting of the control section of the I/O units and the resetting of the output section thereof.
Moreover, the present invention relates to a programmable controller system which is provided with a single or a plurality of CPU units for carrying out the control of the entire system and a plurality of I/O units that are operated under a control of the CPU units, and in such a programmable controller system, the CPU unit writes a command for instructing a control CPU specified information for each I/O unit, each I/O unit decodes a command instructed by the CPU unit so as to determine whether or not it is information specified by the control CPU, and holds the corresponding information specified by the control CPU in the I/O unit, the CPU units issue commands for instructing the reset control to all the I/O units, and each I/O unit decodes the command instructing its reset control, and when it has determined that the corresponding command is instructed from the CPU unit of-the controlling end, it follows the reset controlling instruction so that the resetting operation of the specific I/O unit on the system specified by the CPU unit is controlled. Therefore, only the specific I/O unit on the system that is specified by the CPU unit can be reset.
Moreover, with respect to instructions for issuing a reset to each of the I/O units, the CPU unit is provided with two kinds of instructions for reset-controlling the control section of the I/O unit and for reset-controlling the output section of the I/O unit. Therefore, it is possible to individually reset the control section and the output section of the I/O unit.
Moreover, in the present invention, the I/O unit is provided with a register for latching control CPU specified information and a register for latching information used for resetting only the specific I/O unit on the system specified by the CPU unit. Therefore, it is possible to reset only the specific I/O unit on the system specified by the CPU unit by reference to the contents of the registers.
Moreover, the present invention provides a programmable controller system of a dispersion control type multi-CPU system in which a plurality of CPU units control respectively different I/O units. Therefore, in the programmable controller system of the dispersion control type multi-CPU system, it is possible to reset only the specific I/O unit on the system specified by the CPU unit.
Furthermore, the present invention provides a programmable controller system of a redundant control type multi-CPU system containing a stand-by CPU unit which, when any one of the duty CPU units that are currently operated is stopped due to an error, is operated in place of the stopped CPU unit. Therefore, in the programmable controller system of the redundant control type multi-CPU system, it is possible to reset only the specific I/O unit on the system specified by the CPU unit.
The present invention relates to a programmable controller system which is provided with a single or a plurality of CPU units for carrying out the control of the entire system and a plurality of I/O units that are operated under a control of the CPU units, and in such a programmable controller system, the CPU unit is provided with an outputting unit that outputs a signal for reset-controlling the control section of the I/O unit as a reset signal to be transmitted to the entire system and an outputting unit that outputs a signal for reset-controlling the output section of the I/O unit so that the resetting operation of the I/O unit is individually carried out between the control section and the output section. Therefore, the resetting control of the I/O units in the entire system is carried out in a divided manner between the resetting of the control section of the I/O unit and the resetting of the output section.
Moreover, the present invention relates to a programmable controller system of a dispersion control type multi-CPU system in which a plurality of CPU units control individually different I/O units, and in this system, one of the plurality of CPU units carries out the resetting control in a unified manner. Therefore, in the programmable controller system of the dispersion control type multi CPU system, the resetting control of the I/O units in the entire system is carried out in a divided manner between the resetting of the control section of the I/O unit and the resetting of the output section.
Furthermore, the present invention provides a programmable controller system of a redundant control type multi-CPU system containing a stand-by CPU unit which, when any one of the duty CPU units that are currently operated is stopped due to an error, is operated in place of the stopped CPU unit. Therefore, in the programmable controller system of the redundant control type multi-CPU system, the resetting control of the I/O units in the entire system is carried out in a divided manner between the resetting of the control section of the I/O unit and the resetting of the output section.